817 research outputs found

    Non Abelian BF theories with sources and 2-D gravity

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    We study the interaction of non-Abelian topological BFBF theories defined on two dimensional manifolds with point sources carrying non-Abelian charges. We identify the most general solution for the field equations on simply and multiply connected two-manifolds. Taking the particular choice of the so-called extended Poincar\'e group as the gauge group we discuss how recent discussions of two dimensional gravity models do fit in this formalism.Comment: 20 pages, Latex, To appear in Phys Rev D5

    Evaluación del efecto tóxico de los extractos vegetales acuosos Barbasco (Phyllantus sp.) Neem (Azadirachta indica) y Marigol (Tagetes patula) sobre los microorganismos Trichoderma sp. y Metarhizium sp.

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    El experimento se llevó a cabo en el Laboratorio de Fitopatología del Centro de Investigación Natfaima de Corpoica, localizado en el municiplo de El Espinal, departamento del Tolima, entre los meses de marzo y agosto de 2003, Para la piueba se utilizaron extractos vegetales acuosos de Neem (Azadirachía indican), Marigol (Tagetes patula)] y Barbasco [Phylanthus ichihyomelhlus) y los microorganismos biocontroladores Irichoderma sp y Metarhizium so. Bajo condiciones de laboratorio se evaluaron cinco concentraciones (0%. 5%, 10%, 15% y 20%) de cada uno de los tres extractos Gicuosos, frente al crecimiento de los dos microorganismos biocontroladores. Se evaluaron las variables tasa de crecimiento (Crecimiento radial de los hongos biocontraladores) y el valor de la concentración mínima de inhibición. Se ulilizó un diseño completamente al azar y las observaciones se analizaron mediante pruebas de regresión y correlación. En conclusión se puede afirmar que ninguno de los tres extractos en las concentraciones evaluadas, afectan severamente a los hongos Metarhizium so. y Trichoderma sal y que tanto el Neern como el Margo! en concentaciones superiores al 20% puede lener un efecto funguiciaa contra el hongo Trchoaerma so. Igualmente con respecto a Marigel, es posible que en concentraciones más altas, tenga efectos tóxicos sobre el Metarhizlumn sp

    Free Abelian 2-Form Gauge Theory: BRST Approach

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    We discuss various symmetry properties of the Lagrangian density of a four (3 + 1)-dimensional (4D) free Abelian 2-form gauge theory within the framework of Becchi-Rouet-Stora-Tyutin (BRST) formalism. The present free Abelian gauge theory is endowed with a Curci-Ferrari type condition which happens to be a key signature of the 4D non-Abelian 1-form gauge theory. In fact, it is due to the above condition that the nilpotent BRST and anti-BRST symmetries of the theory are found to be absolutely anticommuting in nature. For our present 2-form gauge theory, we discuss the BRST, anti-BRST, ghost and discrete symmetry properties of the Lagrangian densities and derive the corresponding conserved charges. The algebraic structure, obeyed by the above conserved charges, is deduced and the constraint analysis is performed with the help of the physicality criteria where the conserved and nilpotent (anti-)BRST charges play completely independent roles. These physicality conditions lead to the derivation of the above Curci-Ferrari type restriction, within the framework of BRST formalism, from the constraint analysis.Comment: LaTeX file, 21 pages, journal referenc

    First evidence of coherent K+K^{+} meson production in neutrino-nucleus scattering

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    Neutrino-induced charged-current coherent kaon production, νμAμK+A\nu_{\mu}A\rightarrow\mu^{-}K^{+}A, is a rare, inelastic electroweak process that brings a K+K^+ on shell and leaves the target nucleus intact in its ground state. This process is significantly lower in rate than neutrino-induced charged-current coherent pion production, because of Cabibbo suppression and a kinematic suppression due to the larger kaon mass. We search for such events in the scintillator tracker of MINERvA by observing the final state K+K^+, μ\mu^- and no other detector activity, and by using the kinematics of the final state particles to reconstruct the small momentum transfer to the nucleus, which is a model-independent characteristic of coherent scattering. We find the first experimental evidence for the process at 3σ3\sigma significance.Comment: added ancillary file with information about the six kaon candidate

    Towards a Proof Theory of G\"odel Modal Logics

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    Analytic proof calculi are introduced for box and diamond fragments of basic modal fuzzy logics that combine the Kripke semantics of modal logic K with the many-valued semantics of G\"odel logic. The calculi are used to establish completeness and complexity results for these fragments

    Variation in Seed Dormancy Quantitative Trait Loci in Arabidopsis thaliana Originating from One Site

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    A Quantitative Trait Locus (QTL) analysis was performed using two novel Recombinant Inbred Line (RIL) populations, derived from the progeny between two Arabidopsis thaliana genotypes collected at the same site in Kyoto (Japan) crossed with the reference laboratory strain Landsberg erecta (Ler). We used these two RIL populations to determine the genetic basis of seed dormancy and flowering time, which are assumed to be the main traits controlling life history variation in Arabidopsis. The analysis revealed quantitative variation for seed dormancy that is associated with allelic variation at the seed dormancy QTL DOG1 (for Delay Of Germination 1) in one population and at DOG6 in both. These DOG QTL have been previously identified using mapping populations derived from accessions collected at different sites around the world. Genetic variation within a population may enhance its ability to respond accurately to variation within and between seasons. In contrast, variation for flowering time, which also segregated within each mapping population, is mainly governed by the same QTL
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